In-law and step-family name chart

Most English speakers say sister-in-law, and that is understood, but strictly she is your husband's sister-in-law rather than yours: you are connected through two marriages, not one. English has no separate word for it. The chart below marks every relationship like this, where common usage stretches a term further than its strict meaning.

63 of the 100 relationships in this chart have no single dedicated word in everyday English. People reach for the nearest term instead, which is why the same phrase can mean several different connections depending on who is speaking.

Yes, if the connection is by marriage rather than birth. Your step-parent's child from another relationship is your stepbrother or stepsister, and you share no ancestor. If a parent and step-parent later have a child together, that child is your half-sibling, because you do share one parent.

Socially that varies, but for record-keeping the relationship existed while the marriage did, and a tree should keep it. The connection is what explains why a person appears in a household, a will or a burial plot decades later, so deleting it usually removes the evidence rather than tidying it.

The parents of your child's spouse: your child married theirs, so you are connected only through that marriage. English has no term at all, though several other languages do. Records sometimes name these people as witnesses or executors, which is often the only clue that the families were linked.